1. FIELD OF THE INVENTION
The present invention relates to an improved card clothing for carding machines, including a plurality of card wire teeth arranged in rows and set into a card fillet, which wire teeth are shaped to have a base section, a first point including a first tip and projecting from one end of the base section, and a second point including a second tip projecting from the opposite end of the base section.
2. DESCRIPTION OF THE PRIOR ART
The German industrial standards define in the standards sheet DIN 64 108 the terms and the secondary terms of card fillets, which disclose specifically the various methods of setting the wires. For card clothing which finds application on textile carding machines a preferred pattern is the so-called diagonal stitch wire setting of the card clothing. This diagonal stitch is defined and explained on page 2, cipher 2.2. of mentioned DIN 64 108. The diagonal stitch is mainly set as 4-diagonal stitch or 6-diagonal stitch. In case of a 4-diagonal stitch a respective second row of teeth is laterally offset or displaced, respectively, regarding the first row of teeth by 1/2 width of the teeth (l/2). This displacement corresponds to the width of lane g.sub.1. In case of a 6-diagonal stitch a second row of teeth is displaced relative to a respective first row of teeth by 1/3 width of lane (l/2). A combination of diagonal stitches, i.e. an alternating use of a 4-diagonal stitch and 6-diagonal stitch is, for instance, used, too.
These stitch patterns incorporate, however, the drawback that they have always a free lane extending in the direction of the flow of fibers through the card clothing from the leading end to the trailing end of the card clothing. Due to this design individual fibers are not engaged to during the carding operation, i.e. they flow in an uncontrollable manner through the cleaning and parallelizing process, which obviously leads to the fact that neps and other contaminating matter present in the fibers being processed are not combed out.
The European patent application No. 80'10'3579 (publication No. 0041076) published on Dec. 9, 1981 discloses a card clothing in which at least two teeth formed by the card wires trailing each other in direction of fiber flow are located laterally displaced relative to each other seen in fiber flow by a distance which is not larger than the wire gauge of the card wire such that the card clothing has no free lanes. Mentioned European patent application discloses a card clothing which prevents the forming of lanes by means of a suitable wire setting pattern. In utilizing such stitch pattern it has been found that indeed a higher or better, respectively, removal of contaminations is arrived at during the carding operation and that, furthermore, a substantially increased degree of parallelism can be arrived at.
This has now led to the situation, that at the side of entry of the fibers into the card clothing on the fillet, i.e. at the leading end of each fillet, a damming effect of the fibers to be processed was produced. This damming effect causes now that the respective trailing teeth of the card clothing will not be utilized optimally, i.e. do not satisfactorily fulfill the object of separating or removing, respectively, contaminants and this damming effect has a detrimental influence on the carding process. The higher the throughput capacity of the carding machine is the stronger this damming effect will appear.